Transit Duration Variation Budgets and the Timing-Duration Combination for Exomoons

This paper computes a quantitative budget for one aspect of exomoon physics: the subject stated in the title, evaluated from stated assumptions with every number produced by the deposited calculation. Headline results are tdv_earthmoon_jupiter_s = 54; tdv_fraction_percent = 0.12; tdv_ganymede_s = 7.1; tdv_earth_moon_s = 20. Where a moon displaces its planet along the orbit, it also changes the planet's velocity across the stellar disc. A planet moving faster at transit crosses in less time; moving slower, it takes longer. The resulting transit duration variation is the velocity counterpart of the timing displacement, and the two signals together are far more diagnostic than either alone, because their ratio depends o The results are compared with published Solar System values and with the constraints attached to reported exomoon candidates where those apply, and the conditions under which the computed budget would change are stated explicitly. Computed from stated assumptions, not measured.